1. Field of the Invention
The present invention relates to a complementary metal-oxide-semiconductor (CMOS) power amplifier and a temperature compensation circuit thereof that can be applied to a mobile communications apparatus for mobile communications, and more particularly, to a CMOS power amplifier and a temperature compensation circuit thereof that perform temperature compensation on a gate bias voltage according to a class type of the CMOS power amplifier to thereby perform power amplification in a normal operating region, thereby maintaining constant characteristics regardless of temperature variations.
2. Description of the Related Art
In general, the operating characteristics of power amplifiers are varied according to gate bias values being applied thereto. Especially, the operating characteristics thereof are also varied according to temperature variations.
Temperature variations, determining the characteristics of power amplifiers, occur due to the surrounding environment with operating time according to whether the power amplifiers are operated or not. Therefore, in order to maintain constant operating characteristics, gate bias values of the power amplifiers need to be compensated so that the power amplifiers can perform an amplification operation in a normal operating region.
In the related art, a bias voltage, being applied to a power amplifier, is fixed. However, in the case that a bias voltage is fixed, a gate bias voltage of a power amplifier becomes constant at low or high temperature. As a result, the characteristics of the power amplifier are deteriorated.
Besides, in the related art, there is a method of compensating temperature by using a thermistor in order to perform the temperature compensation of a power amplifier. According to this method, a value depending on temperature variations can be compensated. However, since temperature variations are not considered on the basis of an operating region of the power amplifier, the power amplifier cannot perform amplification in an optimal operating region.